Abstract: An apparatus for controlling an active suspension system for an automotive vehicle comprises hydraulic suspensions, control valves for independently controlling each of the suspensions and a controller for issuing a signal for controlling of opening/closing of the respective control valves. The apparatus includes a longitudinal g sensor for detecting a longitudinal acceleration of a vehicle body and a lateral g sensor for detecting a lateral acceleration of the vehicle. To calculate a control quantity relative to feeding of hydraulic fluid in and discharging of the hydraulic fluid from the respective suspensions required for suppressing pitching and rolling of the vehicle body, the apparatus further includes a control logic which in the controller. A control quantity derived from the circuits is added to another control quantity derived from a vertical g acceleration sensor and a vertical relative displacement sensor, and the resultant control quantity is delivered to the control valve for each suspension.

Abstract: To carry out a method of controlling a plurality of active suspensions for an automotive vehicle, a normal/reverse rolling selection switch and a plurality of correction logics are provided in a control system including a longitudinal acceleration sensor and a lateral acceleration sensor. The correction logics correct a quantity of rolling moment, a variation of suspension reactive force, a control quantity of fluid and variation of a reference vehicle height. A signal from the lateral acceleration sensor and a signal from the normal/reverse rolling selection switch are inputted into a reference vehicle height correcting circuit to control a reference vehicle height corresponding to each active suspension.

Abstract: Vehicle height control for a motor vehicle which has height adjusting means for each of wheel suspensions and which is stationary on a distorted road surface. Height control is carried out for either one of the front wheel suspension pair and the rear wheel suspension pair to attain a reference vehicle height for both the left and right wheels of the one pair whereby the vehicle part having said one pair assumes an attitude parallel to the inclination of the road surface in a direction transverse to the vehicle part. For the other pair of the wheel suspensions, height control is carried out such that the opposite part of the vehicle with the other pair of the wheel suspension will assume an attitude substantially equivalent to the attitude of the first mentioned vehicle part, whereby a good balance is obtained between the contact loads of the wheels.

Abstract: An apparatus for adjusting height of a vehicle includes an incremental-type rotary encoder operated as a sensor for sensing the height of the vehicle. The incremental-type rotary encoder comprises a rotary disc having two sets of slits positioned at circumferential portions having different radii each other and different phase of 90.degree. in a rotating direction of the rotary disc. The incremental-type rotary encoder is further provided with a slit having a semi-circular shape disposed along a circumferential periphery thereof. A neutral position of an operation range of the rotary disc is determined as a boundary of the location of the semi-circular slit. The semi-circular slit is detected to discriminate whether height of the vehicle is above or below the neutral position of the rotary disc. A height adjusting mechanism is displaced in a vertical direction according to data from a detector. The apparatus controls the rotating direction and the amount of the rotation of the rotary disc.

Abstract: An active suspension of a motor vehicle is controlled by a system and a method which comprise combining a controller and an actual flow quantity estimation circuit for estimating by logic operation the flow quantity of the fluid actually flowing through each control valve of the suspension with respect to a total desired flow quantity, and calculating the difference between the actual flow quantity value thus estimated and the desired flow quantity, thereby correcting the desired flow quantity. A command signals is generated and transmitted in accordance with the desired flow quantity thus corrected for operating the control valve to undergo opening/closing operation.

Abstract: An active fluid suspension system has a controller for controlling the delivery and withdrawal of air to and from individual suspension units at vehicle wheels in response to the sensor output signals representing a prescribed set of vehicle behaviors. The controller includes insensitivity zone filters each for filtering out those portions of one sensor output signal of which amplitudes are within an insensitivity zone, thereby avoiding unnecessary fluid flow into and out of the suspension units. The insensitivity zone is defined as a range of amplitudes between given positive and negative values. The filters widen the insensitivity zones with an increase in vehicle speed for optimum suspension control in all vehicle speed ranges.